1990 Volume 5 Issue 5 Pages 639-649
Plasma angiotensin II levels were examined in rats, rabbits and dogs after single i.v. administration or i.v. infusion. The plasma concentrations were determined by radioimmunoassay.
1. After single i.v. administration of 0.1, 1.0 and 10.Oμg/kg to male and female rats, the plasma concentrations declined rapidly with half-lives (T1/2) of 11.9-19.1sec.
2. After single i.v. administration of 1μg/kg to rabbits and dogs, their profiles of plasma concentration-time curve were similar to that of rats, and declined with T1/2 of 23.4 and 26.8 sec, respectively.
3. After i.v. infusion of 1μg/kg/min for 15min in rats and dogs, the plasma concentrations declined in similar manner as after single i.v. administration. The T1/2 were regarded to be equal after both administration methods.
4. After consecutive administrations to rats and dogs for 7 days, no significant accumulation occurred in the plasma concentrations. A similar concentration-time curves were obtained between lth and 7th day.
5. After single i.v. administration to nephrectomized rats, the plasma concentration was not different from that of normal rats.
6. In vitro plasma protein binding ratios of angiotensin II in rats, dogs and human were 42.9, 58.3 and 57.9%, respectively. In vivo plasma protein binding ratios were 48.0% in rats at 15sec after single i.v. administration and 60.0% in dogs at 15min after beginning of i.v. infusion.
